OK, so I was a bit confused about the edges in Max as over at Autodesk they said I had to clean them up. Someone from there cleaned one up and the edges were totally different and looked much more “clean”.
So I opened your model in SU and then imported it into Max as SKP V8 and it looked really nice (thanks!) then created the UV for it except for the windows (going to work more on it tomorrow, still slow with this stuff as I am very new to all this). I then exported it to Quixel as a FBX file and with a 4096x4096 UV and it showed up nicely with no issues.
So do you think it is mostly because of the wall thickness? I think it was also an issue with the windows being flat with the rest of the model, but not sure about that. For my shop model I will try to fix it tomorrow as well, that one is vastly more complicated so there is a lot more to watch for.
So how exactly did you thicken the walls in SU?
Once I get this all figured out I can finally kick it in afterburner and finally complete my workflow. I have been stuck on trying to figure this one problem out for over two weeks to no avail but what you did looks like it may very well be the answer to it.
Thanks for the help!